Dolomite
Dolomite is a mineral containing calcium and magnesium carbonates. Granular water treatment grades can dissolve on contact with water, contributing to its mineral content and pH balance.
Natural dolomite and heat-treated, half-calcined dolomite are different materials. Heat treatment changes dissolution behavior. Calcite, which contains calcium carbonate alone, is also distinct from dolomite.
Technical Specifications
| Material class | Half-calcined dolomite |
|---|---|
| Grain structure | Porous mineral granules |
| Fine-grade particle size range | 0.5–2.5 mm |
| Bulk density | 1,110 kg/m³ |
| Calcium carbonate (CaCO₃) | 69.3% |
| Magnesium oxide (MgO) | 25.1% |
| Particle density | 3.32 g/cm³ |
Application and use
- Reactive dolomite grades are considered in fixed-bed treatment of acidic water.
- For reverse-osmosis permeate remineralization, calcium, magnesium and alkalinity targets determine whether the selected grade fits the process.
- Outlet pH and hardness are monitored as the bed dissolves, and replenishment is planned from actual consumption.
Frequently asked questions
Which dolomite is suitable for reverse-osmosis permeate?
Natural and half-calcined dolomite are different materials. Select a verified composition against the target calcium, magnesium, alkalinity and pH.
Can a calcite design be reused for dolomite?
Not directly. Calcite is calcium carbonate; dolomite also contains magnesium, and processing changes its reaction. Review the contact conditions again.
Will this medium reduce hardness?
No. Mineral contact can add calcium and/or magnesium to the water. Consider a separate process when hardness reduction is required.
Is the medium consumed, and when should it be topped up?
A reactive neutralization bed is consumed as it dissolves. Set replenishment from bed-level checks and treated-water pH and mineral targets.
Is every dolomite filter medium automatically suitable for drinking water?
No. Check the exact natural or processed grade’s water-contact documentation and its registration for the intended market.